Airship propeller



Mayl 6 1924.

. 1,493,324 E. G. DOLAND AIRSHIP PROPELLER Filed Aug. 25. 1922 `4 2 Sheets-Sheet 1 A TTOHIVE YS May 6 1924, 1,493,324

E. G. DOLAND AIRSHIP PROPELLER Filed Aug. 23, 1922. 2 Sheets-Sheet 2 W l TVESSES V /NVENTR I Eben GamwgeD .v1 a U' @ma BQmsz Patented May 6, 1924.

Nl-'rao STATI-:s

PATENT oifFfFicE.

EBEN GEORGE DoLANn' oF sr'ARKsBoRo," VERMONT.'

AIRSHI'P PROPELLER.

Application flied August 23, 1922.

To all whom t may concern:

Be it known that LEBEN GEORGE DOLAND, a citizen of the United States,and a resident of Starlrsboro, in the county of Addison and State of Vermont, havev invented a 'new "and Improved AirshipfPropeller, 'of which the following is a 'full7 clear, and exact description.

This invention relates to p'ropellers for airships, and more particularly aims to provide a new and improved propeller of the ployment of variousmechanisms in lassociation with the fixed support, the revoluble support, and a blade, asrheretofore suggested, wherebythe bla-deis automatically variously tilted atdifferent points in the "course of 'a complete revolution of the revoluble support; thus permitting the blade to'act almost'lilre-a birds'wing. That is to say, the blade being adjustable to have a large angle of incidence on the downward sweep thereof and a very small angle of incidence on its upward sweep, may act 'in a lifting aswell asapropelling capacity and will generally show increased efficiency when considered solely as apropeller.

An important object of the present invention is to provide such la propeller, one simply constructed and positively controlled andv having associated therewith new and improved controlling mechanism of sturdy 'and reliable construction lvandvery compactly carried, and particularly so carried asto reduce head resistance to la minimum. Y

A further object of the invention is to provide an arrangement such as that described and one lalso including means for automatically forcibly urging a lblade vat the requiredinsta-nt to assume a particular degree of tilt `which would otherwise have to be'made unaided against the resistance of the atmosphere to an increased angle of incidence "of the blade. By the provision of such a means Stresses and strains on the controlling mechanism,y on the vrevoluiole fra-me fand on the Abladeitself areflargely overcome.' i

lplane bodyj or fuselage. or -moreof'such framesjto'gether with the Seriallto.r 583,756.

The objects above named `=`will fbe I better understood and -hownfarf the' present-f inventionl goes to satisfy' them, willf bey more' 'clearly appreciated upon reference vrto'the-following description t'o" bet-aken' in [connection with the accompanying drawings'fsliowing an illustrative' embodiment ofthe-invention as now preferred.

With theseobfjects'aud othersin view,

'howeverhthe invention consists in f the` arrangement of elementsfand combinations of parts as ldefined in the=appen`ded claims; and, ofcourse, the invention 'isnotto Tbe restricted to the precise details `'of-construction disclosed Orsuggested herein in -connection with the description of the'exemplifyin'g subject matter ofthe drawings.

Inf'these drawings in'which like 'reference characters' designate the ysarneparts in the several viewsv v Figure l is a longitudinal forffore-andlaft section' taken' on line "1l-1 'ofFigure 3;

Fig. 2 is a View similar to Fig. '1,5but

taken on line 9,-?2" of Fig. 3;

Fig. 3 'is "a horizontal section itaken'on line 3 8 of Fig. l; and

Fig. 4 is ya transverse vertical-section 'taken onfline HfofFig; l. f

Now referring Eto the A'drawirrg`-s, a "supportorframe' 6 isfrevolubleabout a median horizontal axis by virtue of being secured'on a shaft 7V journaled at oppositef-endsfin'suitable stay-members '8 'andBlirunning foreand-aft of the aeroplane body. 'In the present 'oase the foreiandiaft vcenter 'line offthe aeroplane may be assumed to lbe flocated somewhere above and parallell with Stay member 8a of rFig. l ;"a'nolv the elements shown may be assumed to re'pres'entoiie of apair of 'propellers arranged likea pair ofbird wings onopposite sides of ja central aero- Of course, two

associated i parts" t0l ib@ fbelow described, may be eIIlfPlOyed; but the descriptionliere given `will be confined to 'a single ygroup of such elements 'as 'tending to 'simplify th'e dis` closure. It will 'be'understood further that 'if a pair'of such groups is employed, they will be arranged on 'the'ae'roplane in balanced' relation, but preferably' with the axes of rotation of e'ach frame and bladeof each group parallel. For convenience of eX-` lplanation, the airship is herea'ssumedto be los v.leftvof Figs. and3 and thelfra-me.-9iis'fas-v f sumed to be revolving in the direction indicated by the arrow in F ig. 1.

The frame or support 6 is rectangular and elongated in a fore-and-aft direction when taking the horizontal during each of its revolutions.

This revoluble support or frame 6 carries a pair of vanes, blades or wings 9. The number of blades here employed is two, but, of course, one or any number may be used. In ease more than two blades are provided to be driven about shaft 7, and such blades are as large as the blades illustrated, as is preferred, one or more frames similar to the frame 6 may be carried by shaft 7 with the blades suitably angularly spaced and intersecting at shaft 7. The two blades illustrated are advantageouslyv employed as shown, however, each blade 9 being elongated transversely to the frame and each blade having a width almost as great as one-half the length of the frame. Such an efficient structure is rendered practicable by the provision, according to the present invention, of the particularly simple and rugged means disclosed and hereinafter in detail described, for controlling the various tiltings of the blades, and is further made practical by the provision of automatically functioning means, also described in detail hereinafter, adapted automatically to properly assist in the tilting 0f a blade 9 to change its tilt in such a way as ordinarily would meet with increased air resistance due to enlarging the angle of incidence of such blade.

Each blade 9 is secured to a shaft 10 journaled at its opposite ends in side-frames 6a and 6b of the frame 6. The shaft 10 for each blade is preferably at the middle of the blade.

In order to revolve the frame to sweep the blades through circular paths. a chain 11 may be provided driven from a suitable source of power (not shown) and running over a sprocket 12 iiXed on shaft 7.

The controlling mechanism for the blades 9 to cause them to feather or change their angle of incidence, as they commence their forward and backward sweeps relative to the direction of flight of the aeroplane, includes the following parts: A continuous cam-rib 13 providing continuous inner and outer cam surfaces is formed on a disk-like member or plate 14, fixed, as shown, on stay member 8 of the aeroplane body. This plate 14 is thus vertically arranged to lie in a fore-and-aft plane and to present minimum head resistance in the line of Hight of the aeroplane.' The shaft 7, of course` passes loosely'through the plate 14. Two pairs ofl rollers 15 engage the cam-rib at diametrically opposite points, one roller of each pair riding against the inner surface of the camrib and the other roller of each pair riding against the outer surfi@ Of such rib. Each roller of the two pairs is suitably mounted, as indicated best in Figs. 2 and 3, for spinning on a slide 16. Two of such slides are provided, each carrying a rack 17. The slides are independently movable and each worksin a pair of guides 18 on the side member 6b of frame 6. The rack 17 of each slide meshes with a spur gear 19 secured on the shaft 10 of the adjacent. blade 9. Thus the guides, racks, slides and gears, as well as the cam-rib and its supporting plate and the rollers or cam followers 15 are all disposed between the side members 6b of frame 6 and the stay member 8 of the aeroplane body.

The cam-rib 13 while continuous, is composed of sub-divisions of different curvatures, but preferably with no abrupt changes of curvature; so that, unlike certain suggestions already made, the composite curvature of such cam-rib in general is preferably of a circular character at first glance, as clearly shown in the drawings, thus preventing sudden and frequent shocks to any part oi the propeller structure. The curvature just described for the cam-rib is that now deemed preferable, but, of course, may be varied largely so long as the ends mentioned arebest attained. The varying curvatures of the cam-rib impart reciprocating movements to the slides 16 and corresponding tiltings of the blades 9, due to the racks 17 on the slides coacting with the spur gears 19 on the blades. As will be seen from the drawings, the arrangement is such, as shown best in Figure 1, that as a blade commences its forward sweep above the shaft 7, the blade advances almost edgewise through the air, and as the blade commences its-backward sweep below the shaft 7, the blade advances flatwise through the air.

The operation of the parts so far described, is believed to be sufficiently clear from the foregoing description. Ity will be seen that the construction is exceedingly simple and located and assembled very conveniently between the revoluble frame and the body of the aeroplane, thus to cut down head resistance to the minimum, while, at the same time, positively acting parts are employed throughout and in su'ch a way that transverse or shearing strains relative to any working part of the controlling means actuated by the travel of the rollers relative to the cam-rib, are entirely absent.

The means for coactingwith said controlling means in order once during each revolution of frame 6 to forcibly urge a blade to assume a tilt setting the blade to a greater angle of incidence than before, and where- Vby sudden shocks to the controlling means and other parts will be further minimized, is here embodied by the provision simply of -a -pair of retractile springs 20 for each blade, the .springs of each blade diverging away 130 from a point of anchorage at the center of the blade and thence running along a flat of the blade to points of anchorage on side members 6aL and 6b of the revoluble frame, as shown with particularclearness in Fig. 8; these points of anchorage being so'- related to the axis of rotation of the associated blade, as best shown in Figs. l and 4f, that while a blade is arranged to cut the air edgewisely as shown at the right of Fig. l, the springs associated with that blade are most expanded and are storing energy to be released to aid the rack and gear means also associated with that blade in Vdoing the comparatively difficult work, during the travel of the blade from the position shown at the right in Fig. 1 to the position shown at the left in Fig. l, of causing the blade to take a quarter turn in a counter-clockwise direction thereby gradually to throw the blade toward and to a condition where it will have flatwise movement against the air. It will be noted, nevertheless, that the Work of shifting the blades toward and away from iiatwise movement through the air, is done solely by the cam and the cam-operated rack and gear means; the springs 20 having.

the sole but exceedingly important function of balancing or compensating for strains on said cam and rack and gear means at all times.

The operation of the propelling and controlling means, with the latter including the intermittently working means described in the last paragraph, should be sufiiciently clear from the foregoing; and it will, therefore, be seen that the present invention provides a construction well adapted to satisfy all the objects set forth. y

I claim l. In a propeller for airships of the type including a revoluble support carrying eccentrically thereon a rotatable propeller blade, the combination of la fixed member carrying a continuous cam surface, and an operative connection to the blade and actuated by relative movement between said cam surface and the revoluble support, thereby to adjust the blade angularly on the support at different points in the path of revolution of the support, said connection including a cam-follower. a rack carrying the cam-follower and reciprocated thereby, and a gear engaging the rack and fixed on the blade concentric with its axis of rotation.

2. In a propeller for airships, comprising a revoluble support, a propeller blade mounted in the frame, a fixed ribbed cam, a sliding rack, a pair of rollers carried by the rack and engaging opposite sides of the ribbed cam, and a pinion on the shaft of the propeller blade and with which the rack engages.

member and the blade to variously tilt the blade on the revoluble support at different points in the path of revolution of the lat-` ter, one of said blade tilts being to move the blade to increase its angle of incidence, and means automatically functioning to forcibly urge the blade thus to increase its angle and so aid said operative connection in tilting the blade to increase its angle of incidence.

lQIn a propeller for airships of the type including a revoluble support carrying eccentrically thereon a rotatable pro-peller blade, the combination of a fixed member, an operative connection between the fixed member and the blade to variously tilt the blade on the revoluble support at different points in the path of revolution of the latter, one of said blade tilts being to move the blade to increase its angle of incidence, and means partially carried by the blade and partially carried by the revoluble member and automatically acting to urge the blade to change its tilt only when the blade is being tilted to increase its angle of incidence.

5. In a propeller for airships of the type including a revoluble support carrying eccentrically thereon a rotatable propeller blade, the combinationof a fixed member, an operative connection between the fixed member and the blade to variously tilt the blade on the revoluble support at different points in the path of revolution of thelatter, one of said blade tilts being to move the blade to increase its angle of incidence, and lspring means connected to the blade and to the revoluble support for urging the blade to assume a different tilt to increase its angle of resistance. f

.6. In a propeller for air ships, in combination, a revoluble frame having a substantially horizontal axis located substantially. midway of its length, a pair of rotatable blades mounted in the frame on longitudinal axes substantially parallel to the frame axis, each said blade being as wide substantially as one-half the length of the frame and the two blades being located on opposite sides of the frame axis, independently movable racks slidably mounted on the frame with one rack substantially in line with the other, gears fixed on theblades, one such gear meshing with each of the racks, a fixed member carrying a continuous cam surface arranged in a plane substantially parallel to the path of revolution ofthe revoluble frame, and cam-followers directly carried by said racks and directly engaging 

